src/sage/geometry/polyhedron/base6.py: Small docstring edits

src/sage/geometry/polyhedron/base6.py

@@ -253,7 +253,7 @@ def plot(self,
             sage: facet.plot()  # optional - sage.plot
             Graphics3d Object
 
-        For 3d plot, we may draw the polygons with rainbow colors, using any of the following ways::
+        For a 3d plot, we may draw the polygons with rainbow colors, using any of the following ways::
 
             sage: cube.plot(polygon='rainbow')  # optional - sage.plot
             Graphics3d Object
@@ -262,9 +262,8 @@ def plot(self,
             sage: cube.plot(fill='rainbow')  # optional - sage.plot
             Graphics3d Object
 
-
-        For 3d plot, the size of a point, the thickness of a line and the width of an arrow
-        are controled by the respective parameters::
+        For a 3d plot, the size of a point, the thickness of a line and the width of an arrow
+        are controlled by the respective parameters::
 
             sage: prism = Polyhedron(vertices=[[0,0,0],[1,0,0],[0,1,0]], rays=[[0,0,1]])
             sage: prism.plot(size=20, thickness=30, width=1)  # optional - sage.plot
@@ -378,7 +377,6 @@ def plot(self,
             ....:     projected_vertices = [sp.transformed_coords[i] for i in indices]
             ....:     assert Polyhedron(projected_vertices).dim() == 2
 
-
         Check that :trac:`31802` is fixed::
 
             sage: halfspace = Polyhedron(rays=[(0, 0, 1)], lines=[(1, 0, 0), (0, 1, 0)])